Over the years, many variations on the electric motor have been used to convert electrical energy into mechanical energy. Despite these many variations, there exists a need for an electric motor with an adjustable amount of torque to suit particular applications. In particular, there is a need for an electric motor that provides a larger amount of torque without increasing the size or weight of the motor. This type of high torque motor would be useful in a variety of applications, including electric vehicles.
One type of electric motor in use today is the axial gap or pancake motor. An axial gap motor uses one or more disk shaped stators fixed to a frame and one or more disk shaped rotors angularly fixed to an output shaft. This design allows the motor to be more compact than radial gap electric motors. Axial gap motors are self-centering due to the magnetic field generated between the rotor disk and stator disk, making them suited for high speed rotation. However, there is a need for an electric motor that benefits from the compact size of axial gap motors, but produces more torque at a low RPM.
Accordingly, it is an object of the present invention to provide an axial gap motor with an increased amount of torque at low RPMs without increasing the size or weight of the motor. It is also an object of the present invention to provide a means of adjusting the torque output of the motor to suit different applications.